To choose the right size bit for your horse or pony, consider both the length and width of the mouthpiece and the shape of your horse’s mouth. The length (usually in inches) of the bit will correlate to the width of a horse’s mouth such as 5" or 5 ½”. When placed on your horse’s head, the bit should rest comfortably at the corners of his mouth. A bit that is too short could pinch the corners of the horse’s mouth and too long if it hangs without a wrinkle in the horses mouth and could slip sideways causing soreness. For Monty’s bit, be sure the horse’s lips completely clear the bit rings by 1/8 inch on each side to assure that the horse’s skin is not pinched as the loose ring works with the rein.